Stepless speed change gear

ABSTRACT

A stepless speed change gear that is small in size, light in weight, simple in construction, secure in operation, long in service life and capable of high-output speed changes. An input shaft crank (3) and an input side member (4) are mounted on an input shaft (1) and an output shaft (2) via a one-way clutch mechanism (100), respectively, and the respective members are coupled to each other by means of an input connecting rod (5) and an output connecting rod (6). Also, a speed-change link (7) is coupled to a junction point (B) of these links at one end thereof, and the other end thereof (Q) is allowed to move to any position within a certain range and to be fixed at that point. Also, the one-way clutch is a rolling bearing clutch. Variable speed change can securely be obtained with a simple mechanism. In a case where the rolling bearing clutch is used, high-output speed change is possible with the stepless speed change gear that is small in size and light in weight.

BACKGROUND OF THE INVENTION

The present invention relates to a stepless speed change gear using oneor more one-way clutches.

There have been many kinds of stepless speed change gears according tothe prior art such as a chain drive type, a traction drive type, a slidecoupling type and so on including a one-way clutch type as illustratedin FIG. 17.

In the stepless speed change gear shown in FIG. 17, a speed change link7' having a movable support point Q' is connected to a transmission link5' which is connected to an input shaft 3' and an input side member 4'which rotates about a center p' of an output shaft of a one-way clutch.However, such a stepless speed change gear is insufficient in linkmechanism and can be used only for transmission of small power.

There are problems in the other type of stepless speed change gears suchas the traction drive type, etc. that not only they have largetransmission loss but also they have large size, heavy weight andcomplicated construction.

SUMMARY OF THE INVENTION

To solve the above mentioned problems in the prior art, the presentinvention intends to provide a stepless speed change gear of simpleconstruction with reliable action, small size and light weight andsuitable for transmitting even large power.

To achieve the above object, a stepless speed change gear according tothe first invention is characterized to comprise: an input shaft; aninput shaft crank being fitted to the input shaft to a right angledirection and being provided with a connecting part; an input connectingrod being connected to the connecting part at one end side and beingprovided with the other end side connecting part; an output connectingrod being connected to the other end side connecting part at one endside and being provided with the other end side connecting part; aone-way clutch to transmit torque to one direction only and beingprovided with an output shaft disposed in the same direction to theinput shaft and an input side member being connected to said the otherend side connecting part of the output connecting rod at one end sideswingably about a center of the output shaft; a speed change link beingconnected to the other end side connecting part of the input connectingrod at one end side and being positioned at an optional position in agiven moving range at the other end side; fixing means to fix the otherend side of the speed change link; the input connecting rod, the outputconnecting rod, the input side member and the speed change link beingswingable in each plain a direction of which is the same as a directionof rotation of the input shaft crank.

In addition to the above features, a stepless speed change gearaccording to the second invention is characterized in that the speedchange link is provided with a second connecting part at the one endside and the output connecting rod is connected to the second connectingpart at the one end side instead of connected to the other endconnecting part of the input connecting rod.

In addition to the features of the first invention, a stepless speedchange gear according to the third invention is characterized in that adisk-like member being fixed to the input shaft at an eccentric positionand a rotating member being supported rotatably on a circumferentialsurface of the disk-like member are comprised instead of the input shaftcrank and the input connecting rod.

In addition to the features of the first invention, a stepless speedchange gear according to the fourth invention is characterized in thatthe other end side of the speed change link moves a given locus rangefrom a position where the output connecting rod becomes orthogonal toboth the speed change link and the input side member to a position wherethe output connecting rod and the speed change link line up in astraight line.

In addition to the features of the first invention, a stepless speedchange gear according to the fifth invention is characterized in thatthe one-way clutch is a rolling bearing clutch comprising an innerrotation body, an outer rotation body, a plurality of intermediaterotation bodies and energizing means; the inner rotation body isprovided with an inner raceway surface of a mono-hyperboloid ofrevolution about an axis of the output shaft; the outer rotation body isprovided with an outer raceway surface of a mono-hyperboloid ofrevolution about the axis; the inner rotation body and the outerrotation body are facing each other to form a raceway; the intermediaterotation bodies have cylindrical rolling surfaces and are disposed inthe circumferential direction of the raceway with their center linesslanting at a predetermined angle to a section including the axis; thesurface of each intermediate rotation body contacts in line with theinner and outer raceway surfaces; the energizing means energize eitherthe inner rotation body or the outer rotation body in the direction ofthe axis to narrow the spacing of the raceway; the inner and outerrotation bodies are provided with an annular member at opposite side inthe axis which brings the movement of the intermediate rotation bodiesin the axis direction to a stop; the outer rotation body is connected tothe input side member so that both rotate in one body; the innerrotation body is connected to said output shaft so that both rotate inone body.

With the stepless speed change gear according to the first invention,the rotation of the input shaft is transmitted to the input connectingrod of which the other end side connecting part is connected to thespeed change link which is positioned by the fixing means at the otherend side and is swinged about the fixed point. This movement of theother end side connecting part of the input connecting rod istransmitted to the input side member of the one-way clutch via theoutput connecting rod, which swings the input member about the outputshaft as the center. As a result, the output shaft is rotatedintermittently under the function of the one-way clutch mechanism. Inthis case, by transferring the position of the fixed point of the speedchange link, the direction of the swing motion is changed, which changesthe width of swing of the input side member. Thus, the speed changeratio is altered. And, as the speed change link can be fixed at theoptional point of given movable range by the fixing means, the abovespeed transmission is stepless.

Further, although the rotation of the output shaft transmitted via theinput side member and the one-way clutch mechanism is intermittent, itcan be smoothed by using a plurality of the one-way clutches or byinstalling a flywheel. Furthermore, one or more gears for increasing ordecreasing speed may be installed additionally to obtain the desiredmaximum or minimum speed change ratio.

With the stepless speed change gear according to the second invention,since the speed change link is provided with the second connecting partat its one end side and the one end side of the output connecting rod isconnected to the second connecting part, while the other end sideconnecting part of the input connecting rod is connected to a differentpoint of the speed change link excepting the second connecting part,different displacement is transmitted to the output connecting rod thanthat of the input connecting rod.

With the stepless speed change gear according to the third invention,since the rotating member is supported rotatably on the circumferentialsurface of the disk-like member, the center of the rotating member moveslike a crank pin when the input shaft is rotated. As a result, the otherend side connecting part of the rotating member swings the speed changelink, whereby the output connecting rod makes reciprocating motion. Thismotion is transmitted to the one-way clutch which rotates the outputshaft at a changed speed same as the first invention.

In the stepless speed change gear according to the fourth invention,when the other end side of the speed change link is positioned where theoutput connecting rod becomes orthogonal to both the speed change linkand the input side member, the swing width of them become maximum, whichgives the maximum speed of the output shaft. On the other hand, when theother end side of the speed change link is positioned where the outputconnecting rod and the speed change link line up in a straight line, theaxial movement of the output connecting rod becomes minimum, which givesthe minimum speed of the output shaft. In this case, when the length ofthe speed change link and the output connecting rod are the same, theswing amount of the input side member become 0 and stopping condition ofthe output shaft can be realized. Since the other end side of the speedchange link is moved in the range as mentioned above, the speed of theoutput shaft from maximum to minimum can be obtained effectively.

With the stepless speed change gear according to the fifth invention,since the rolling bearing clutch is used as the one-way clutch, itsexcellent performance is utilized for the stepless speed change gear asfollows:

As the inner and outer raceway surfaces are both monohyperboloid ofrevolution, the raceway formed by them has the diameter enlarging fromone end to the other end. And, a plurality of intermediate rotationbodies are disposed slanting to the axis section. Therefore, when theswing of the outer rotation body (hereafter called ∠outer ring∠) causedby the rotation of the input shaft crank is free rotation side, theintermediate rotation bodies roll on the inner and outer racewaysurfaces, being guided by them and keeping line contact with them.However, since the advancing direction of the intermediate rotationbodies to the inner raceway surface is opposite to the advancingdirection of the intermediate rotation bodies to the outer racewaysurface, the inner rotation body (hereafter called ∠inner ring∠) and theouter ring are forced to remove each other in their axial directionwhich widens the raceway distance.

On the other hand, since the energizing means energize either the innerring or the outer ring in the direction to narrow the spacing of theraceway, the inner ring and the outer ring face each other in theirradial direction without separating, under receiving the removing forceand the energizing force at the same time. Thus the inner and outerrings rotate relatively via the intermediate rotation bodies. Therefore,the rotation of the input shaft is not transferred to the output shaft,which do not rotate it in this direction of the swing.

Contrary to the above, when the rotation of the outer ring caused by therotation of the input shaft crank is the clutching side, in addition tobe energized by the energizing means, the inner ring or the outer ringis moved to the direction to narrow the spacing of the raceway, by themovement of the intermediate rotation bodies which is contrary to theabove. As a result, the intermediate rotation bodies work as spragsbetween the inner and outer ring, which generates instantaneousclutching action. Thus the rotation of the input shaft crank istransmitted to the output shaft through the rolling bearing clutch andthe output shaft rotates at the changed speed.

In the above rolling bearing clutch, unified load distribution isachieved between the inner ring or the outer ring and the intermediaterotation bodies due to stable line contact between them. Accordingly, itworks as the excellent roller bearing in the free rotation, while itgenerates large clutching force by the wedge effect of the intermediaterotation bodies in the reverse rotation. Further, since the intermediaterotation bodies are aligned automatically in the raceway, uniform loaddistribution is maintained for variation of miscellaneous conditionssuch as deformation of the clutch, wear of the raceway surfaces anddimentional accuracy. Furthermore, as on/off action of the clutch iscarried out mainly by rolling of the intermediate rotation bodies, suchexcellent performances are obtained that stable action is maintained asa clutch in frequent repetitions of on/off motion, long service life isensured for large rated load and transmission of high output isavailable.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an explanatory drawing of a mechanism of a stepless speedchange gear of an illustrative embodiment;

FIG. 2(a), (b) are explanatory drawings of relation of changing speed ofthe stepless speed change gear;

FIG. 3 and FIG. 4 are explanatory drawings to get conditions for stableoperation of the stepless speed change gear;

FIG. 5 is an explanatory drawing to get an error δ at u≠t in thestepless speed change gear;

FIG. 6 is a sectional view showing an example of construction of thestepless speed change gear;

FIG. 7 is a 7--7 line sectional view of FIG. 6;

FIG. 8 is a sectional view showing a connecting part between an outputconnecting rod and a rolling bearing clutch;

FIG. 9 is a sectional view showing a detail of a fitting part of a speedchange link of the stepless speed change gear;

FIG. 10 is a perspective view of an illustrative embodiment of therolling bearing clutch;

FIG. 11 is a perspective view of rollers and an inner ring parts of therolling bearing clutch;

FIGS. 12, 13, 14(a), and 14(b) are sectional views of other embodimentsof the rolling bearing clutch;

FIG. 15 is an explanatory drawing of a mechanism of the stepless speedchange gear of another illustrative embodiment;

FIG. 10 is an explanatory drawing of a method to direct force acting ona supporting point for speed change to an input shaft;

FIG. 17 is an explanatory drawing of the stepless speed change gear ofone-way clutch type in the prior art.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

FIG. 1 shows mechanism of a stepless speed change gear of one preferableembodiment.

An input shaft crank 3 and an input side member 4 via a one-way clutch100 are fitted respectively at an input shaft 1 and an output shaft 2which are at a right angle to this sheet, and also they are connected toeach other by links of an input connecting rod 5 and an outputconnecting rod 6. A speed change link 7 which is positioned at anoptional position Q in a given moving range is connected to theconnecting point B of the input and output connecting rods 5 and 6. Theconnecting parts of the connecting points A, B, C of the crank and linksare pin joints by which the input shaft crank 3, the input side member4, the input connecting rod 5, the output connecting rod 6 and speedchange link 7 are rotatable or swingable in the same direction planewhich are at right angles to the input shaft 1 and the output shaft 2.

In these mechanism, when the input shaft 1 is rotated, the point Bswings to the direction shown by the arrow in the figure about the pointQ as the center by the movement of the input connecting rod 5 and thespeed change link 7. The swing of the point B is transmitted to thepoint C via the output connecting rod 6, which swings the input sidemember 4 about the point P as the center and rotates the output shaft 2intermittently under the function of the one-way clutch 100. In thedrawing, since the output connecting rod 6 is at right angles to boththe input side member 4 and the speed change link 7, the rotating speedof the output shaft 2 becomes maximum, giving maximum transmissionratio.

To change the transmission ratio, the point Q is moved and stopped againat another position. The moving range for transmission may be the rangein which such mechanism can be operated. Accordingly, the locus of themoving range may be such curve as a circular arc, a straight line etc..In the embodiment, the point Q is moved on the circular arc having thecenter O from the view point of ease of manufacturing.

When getting the minimum transmission ratio, the swing center point Q ofthe speed change link 7 is turned around the center O of the input shaftcrank 3 until it reaches the point Q'. Although width or speed of swingof the point B does not change in the movement, the component to swingthe point C in the swing width of the point B changes corresponding tothe movement of the point Q. And finally, when each point Q, B and Creaches to each point Q', B', and C' where the point B', C' and Q' lineup in a straight line, the rotating speed of the output shaft 2 becomesminimum. In this case, the swing width of the outer circumference C' ofone-way clutch 100 which is swing by the swing of the point B' via theoutput connecting rod 6 is δ as shown in FIG. 1. This δ is produced bythe difference of the radius of curvature between the speed change link7 and the output connecting rod 6. However, as this δ is a very smallvalue, the minimum transmitted speed becomes almost 0. Therefore, byadopting the output connecting rod 6 and the speed change link 7 havingthe same length, the complete 0 transmission in which δ and the movementof the point C become 0 can be attained.

By this transmission mechanism, changed speed from 0 a predeterminedvalue can be obtained without any step. Further, the transmitted speedfrom 0 to desired speed can freely obtained by installing, for example,one or more gears for increasing or decreasing speed.

Furthermore, although such output rotation using one-way clutch 100 isintermittent, there is no problem for practical use, because, suchmethod as to make the device multi-stage by providing a plurality of oneway clutches or installing a inertia equipment such as a flywheel may beadopted.

FIGS. 2(a), (b) are explanatory drawings of relation of changing speed.

If the rotating speed of the input shaft crank 3 is constant,circumferential speed V₁ of the point A is constant. Both figure (a),(b) show positions of the point A and A' of the input shaft crank 3wherein the speed of the point B and B' becomes maximum. And (a) showsthe condition of the speed change when each point O, B, and C line up ina straight line and the point Q and P are both on the perpendicular ofthe straight line OBC, resulting in the maximum speed of the outputshaft 2. On the other hand, (b) shows the condition of the speed changewhen each point B', Q' and C' lines up in a straight line and the pointQ' corresponds to the point C, in which the speed of the output shaft 2becomes 0. In the figures, rotation method is used for speed conversionof the circumferential speed V₁ of the point A.

In FIG. 2(a), the circumferential speed V₁ is converted from the point Ato point B as follows; get V₁ =V₁ ' by turning V₁ to the direction AO;get cross point R on the segment BQ by drawing the parallel line to theline AB which starts from the extremity of the vector V₁ '; get crosspoint S by turning the vector V₂ ' 90° and get the segment BS as thevector V₂ of the point B. Further, since the segment BC and PC cross ata right angle, circumferential speed of the point C is the same to thatof the point B in the direction and dimensions, which gives the speedvector V₃ =V₂. As a result, if there is no energy loss in the outputside including the one way clutch 100, the output shaft 2 rotates withthe maximum circumferential speed V₃ at the point C by the given inputspeed V₁.

In FIG. 2(b), also the vector speed V₂ of the point B' is obtained byrotation and conversion of V₁ →V₁ '→V₂ '→V₂ similarly as mentionedabove. In the point C', as the vector V₂ is directing to the straightline B' C' at a right angle, the vector V₃ ' corresponding to the vectorV₃ does not exist. Accordingly, there is no input to the one-way clutch,making the rotation of the output shaft 0.

As described above, when the point Q is transferred to the point Q' byrotation, the circumferential speed of the input side member 4 of theone-way clutch changes from V₃ to 0. Therefore, the speed of the outputshaft 2 can be changed steplessly from V₃ to 0 by making it possible tostop the point Q of the speed change link 7 at any point in its movablerange.

Now, conditions are derived so that the link mechanism work stably byFIG. 3.

As shown in FIG. 3, notations are given as follows: r as the radius ofthe input shaft crank 3; s as the distance between the shaft center ofthe input shaft 1 and the swing center B of the speed change link 7; tas the length of the output connecting rod 6; u as the length of thespeed change link 7; and R as the radius of rotation of the input sidemember 4. The point Q or Q' shows the position when the output shaft 2reaches maximum speed or minimum speed (changed speed 0) respectively.The conditions to get maximum speed are that both the angle OBQ and OCPbecome right angles. The changed speed 0, the following equation isderived to avoid unstable operation when the angle B' Q' P is nearly180°;

    OP≦OQ'+R                                            (1)

and, from the triangle OPQ and OB' Q'; ##EQU1## then, from the equation(1) and (2), as the relations between s, t, u, R; ##EQU2## can beintroduced. Therefore, if these relations are satisfied, the operationof the stepless speed change gear is stabilized.

FIG. 4 shows a case when u≠t. Although it is preferable to be u=t inprinciple, there will be the case that the dimensional difference mustbe provided between u and t for the convenience of the design andmanufacture. In this case, as shown in the FIG. 4, the error δ comes outdue to the radial difference of the rotation between u and t, whichcauses the problem that the rotating speed of the output shaft 2 doesnot become completely 0.

FIG. 5 is a drawing to calculate the error δ. In the drawing, notation wmeans the distance from the swing center Q' of the speed change link 7to the connecting point C' of the input side member 4 and the outputconnecting rod 6, that is, the difference of the radius of rotationbetween the output connecting rod 6 and the speed change link 7, and,notation δu or δt means the axial displacement of the point where is inthe distance r from the swing center B'. Then δ is calculated asfollows; ##EQU3##

The value of δ obtained by the equation (4) is very small when w issmall. Accordingly, when rolling bearing clutch is used as the one wayclutch 100, since the clutch has characteristics as torsion spring fortransmission torque the error δ is absorbed by the torsional angleproduced between the input side member 4 and the output shaft 2,achieving the stepless speed change up to 0 without rotating the outputshaft 2 substantially.

FIGS. 6 and 7 show an example of the construction of the embodiment ofthe stepless speed change gear, wherein FIG. 6 is a sectional view andFIG. 7 is a side view.

The gear in this example is a type wherein two rows of rolling bearingclutches are arranged.

Each of input shaft crank 3, 3 is provided with each crank pin 31, 31and is fixed at each left and right side on an input shaft 1 which issupported by a body frame 10 via bearings. Each input connecting rod 5,5 is connected to each crank pin 31, 31 via each bearing at one end, andconnected to each one end of each output connecting rod 6, 6 via eachcrank pin 51, 51 and each bearing at the other end. These rods are ableto move freely in planes of which directions are the same to therotation plane of the input shaft cranks 3, 3. The other end of eachoutput connecting rod 6, 6 is connected to each input side member 4, 4of each rolling bearing clutch 100, 100. An output shaft 2 operated as acommon shaft of each clutch is rotated one direction only when eachinput side member 4, 4 is swung FIG. 8 shows detail of a connection partto connect the output connecting rod 6 to the rolling bearing clutch 100through the input side member 4.

Each speed change link 7, 7 of which the swing center is each crank pin71, 71 (the point Q in FIG. 7) is connected to each crank pin 51, 51.The crank pin 71 is connected to a ring 11 which is fitted to the bodyframe 10 rotatably about the input shaft 1 as the center and can befixed at any optional point by being rotated on the body frame 10through bearings, thus making available the stepless speed change.Further, as shown in the figure, since the ball bearings are used atmain parts of the construction, the variable transmission is free frommaintenance as for lubrication. And also, problems of backlash do notarise because a gear mechanism is not used.

FIG. 9 shows a detailed construction of a fitting portion of the crankpin 71 of the speed change link 7 to the ring 11. By connecting thespeed change link 7 and the ring 11 as shown in the figure, the supportpoint Q for transmission can be shifted by rotating the ring 11. Theshifting and fixing of the ring 11 is carried out by turning a lever 12as shown in FIGS. 6 and 7. That is, the lever 12 is fixed at any point,by rotating a handle 13 to one direction to loose a friction member 14from contacting to the body frame 10 with pressure, then by rotating thehandle 13 to the other direction to push the friction member 14 to thebody frame 10 with pressure. By such a method, the support point forspeed change can be fixed at any point between Q and Q' (transmissionrange 70° ). Accordingly, the ring 11 and the lever 12 are examples ofthe fixing means. However, other suitable methods may be adopted asfixing means, for example, a worm gear being engaged with a worm wheelwhich is provided at the circumference of the ring 11 except the abovemethod as utilizing friction. Further, the fixing means may be operatedremotely or automatically in order to control transmission ratio.

Furthermore, although the above embodiment has two sets of the rollingbearing clutches, the stepless speed change gear may be formed as amulti-stage unit having more than 3 clutches. By making a multi-stageunit, the output rotation is smoother.

It is explained now about the rolling bearing clutch which can be usedfor the stepless speed change gear of the present invention.

FIG. 10 shows general construction of the rolling bearing clutch andFIG. 11 shows a part of the clutch.

An inner ring 101 corresponding to the inner rotation body is movably onan output shaft 2 by a key engagement 105. An outer ring 102corresponding to the outer rotation body is disposed facing the innerring 101 to form a raceway 109.

A plurality of rollers 103 corresponding to the intermediate rotationbody are, as shown in FIG. 11, disposed in the raceway 109 slanting to aplane including a center line 106 of the output shaft 2 at an angle of β(e.g. 15 degree).

The inner ring 101 is pushed by the outer ring 102 via a combination ofa plate spring 107 and a spring retainer ring 108 as one example of theenergizing means, to a direction to narrow the space of the raceway 109(from right to left in the drawing). And, in this embodiment, since theouter ring 102 and the input side member 4 are constructed in one body,the rotation of the input shaft 1 is transmitted to the outer ring 102.

From the above configuration, in the free rotation (counterclockwise orleft rotation of the outer ring 102 viewing from the right end side inthe drawing), the rollers 103 which rotate to the left contacting withthe inner and outer rings advance the inner ring 101 to the rightdirection against a energizing force of the plate spring 107, enlargingthe space of the raceway 109. In other words, an action of the taperedscrew will be produced between the inner and outer rings 101 and 102 viathe rollers 103. The action will cause a right direction advancement ofthe inner ring 101 relative to the outer ring 102 based on the principleof unthreading of the screw, which enlarge the space of the raceway 109.As a result, the inner ring 101 can be freely rotated without causingwedge action of the rollers 103 between the raceway 109. Therefore, whenthe input rotation of the input shaft crank 3 of the stepless speedchange gear shown in FIG. 6 is transmitted to the outer ring 102, onlythe outer ring 102 rotates without rotating the inner ring 101 and theoutput shaft 2.

Meanwhile, in this free rotation condition, the rollers 103 receiveaxial force of different strength from the inner and outer rings 101 and102 in the opposite directions, which moves the rollers 103 in the axialdirection. However, since the difference of the strength of the forceproduced by the inner or outer ring 101 or 102 is small, both the innerand outer rings 101 and 102 are provided with flanges 110 and 112respectively as the annular member at opposite sides in the center line106 to prevent the rollers 103 to disengage with the inner or outerring.

On the other hand, in the reverse rotation condition (the outer ring 102rotates clockwise viewing from right), the movement of the componentsare contrary to the above description: the rollers 103 rotate to theright, retreating the inner ring 101 to the left direction withoutadvancing it. The compression force of the plate spring 107 moves theinner ring 101 to the left relative to the outer ring 102 to narrow thespace of the raceway 109. The action causes the rollers 103 to be lockedin the raceway 109 and a wedge effect is produced. As a result, theinner ring 101 and the outer ring 102 are clutched as soon as thereversal rotation is started. Thus the input rotation to the steplessspeed change gear is transmitted to the output shaft 2 immediately,which is rotated at the predetermined changed speed. Therefore, highefficiency (more than 90% by the experiments) is obtained in the speedchange with little heat generation.

In FIG. 11, the rollers 103 are arranged on the inner ring 101 slantingto a section including the center line 106 thereof by an angle of β, andthe rollers 103 are retained in place by a retainer 111 to keep them offof each other. This configuration can prevent adjacent rollers 103,rotating in a same direction, from running against each other withrelative tangential speed in an opposite direction, resulting in asmooth rotation of the rollers 103 and a smooth revolution thereofaround the inner ring 101.

As described above, when torque is transmitted from the input shaft tothe output shaft through the contact between the inner or outer ring andthe rollers, they must be contacted in a line in order to transmit largetorque for a long time under the condition of frequent clutching andde-clutching. Therefore, the rolling surface of the rollers 103 iscylindrical and the raceway surfaces 101a and 102a of the inner andouter rings 101 and 102 are a mono-hyperboloid of revolution about thecenter line 106 which are given by the following equations;

    yi.sup.2 /ai.sup.2 -xi.sup.2 /bi.sup.2 =1                  (5)

    yo.sup.2 /ao.sup.2 -xo.sup.2 /bo.sup.2 =1                  (6)

In the above equations, each notation means as follows: xi or xo meansdistance of the inner or outer raceway surface 101a or 102a from eachsmall diameter end to the direction of the center line 106; yi or yomeans distance of the inner or outer raceway surface 101a or 102a fromthe center line 106 in the optional section including the center line106; ai, bi, ao or bo means a constant. Further, designating F asdistance from the center line 106 to the center of the rollers 103 inthe base face of the small diameter end of the inner and outer rings, ras the radius of the rollers 103 and β as the slanting angle, andassuming that F=9, t=1.5 and β=15° for example, each value of ai, bi, aoor bo in the above equations is calculated to be 7.5, 30.1, 10.5 or 37respectively (calculation is not described because it is complicated.Thus, the shape of the mono-hyperboloid of revolution of the inner andouter raceway surfaces are decided.

The rollers may be conical shape or hourglass or convex drum shape whichis symmetrical to its longitudinal center having a surface ofmono-hyperboloid of revolution, instead of the cylindrical shape asmentioned above. In this case, both the inner and outer raceway surfacesare a mono-hyperboloid of revolution.

Although each of the rollers 103 is formed as one piece in the aboveembodiment, it can be divided into a plurality of pieces in its axialdirection. Such configuration enhances the performance in the freerotation by enhanced skewness and reduced rolling resistance andincrease adaptability for alignment and dimensional accuracy.

FIGS. 12, 13, 14(a), and 14(b) show other embodiments of the rollingbearing clutch, the inner ring 101 of which does not move in the axialdirection.

A space between the inner and outer rings 101 and 102 is formed as araceway 109 wherein cylindrical rollers 3 are retained by a retainer111.

On one end of the inner ring 101 where there is one end side of theouter ring 102, a housing 4, as the input side member of the steplessspeed change gear, is disposed via a thrust bearing 113. The housing 4is mounted on the inner ring 101 through a thrust bearing 113 fixedly inthe axial direction and rotatably. Further, the housing 4 is soconnected to the outer ring 102 as to rotate integrally therewiththrough torque transmission means such as a torque transmission pin 114(FIG. 12), an involute spline 115 (FIG. 13), ball spline 116 (FIG.14(a)), etc. A coil spring 107 or a plate spring 107 corresponding to apre-compression spring as energizing means is provided between thehousing 4 and the outer ring 102, delivering pre-compression force tothe outer ring 102.

Using of such construction that the inner ring 101 and the housing 4 donot move in the axial direction brings easy fitting of the steplessspeed change gear both in its input and output sides. In this occasion,the clutching action is produced by arranging the outer ring 102 movablyin axial direction.

By using the rolling bearing clutch as a one-way clutch as describedabove, wherein the rollers 103 are intentionally slanted to the planeincluding the center line 106 of the inner and outer rings, and rotateson their axis on the inner and outer raceway surfaces 101a and 102amaintaining stable line contact with them and also revolve around thecenter line 106, excellent load distribution can be obtained. In thiscase, even if there should be a dimensional error in the rollers 103, orvariation in force previously applied by the plate spring 107 in thestart operation, the rollers 103 can change their attitude so that allthe rollers would participate in the carriage of the load, thusachieving automatically unified load distribution. Therefore, the clutchmachined with a general machining accuracy can realize calculated loaddistribution, which brings unified clutching between the inner and outerrings through all of the rollers.

Further, the rollers 103 function as rolling members of a bearing bytheir rotation and revolution in the free rotation, while they operateimmediately for clutching under the action of the energizing means andtheir automatic aligning action in the reverse rotation. Therefore, ifthere should occur deformation of the inner and outer raceway surfacesor wear of rollers or raceway surfaces due to frequent on/off operationof the clutch, the inner ring 101, the outer ring 102 or the rollers 103can change their axial situations without affecting the clutchoperation. Accordingly, it is not necessary either to increase the wallthickness of the inner and outer rings to ensure the rigidity forexternal or internal pressure added to the rings, or to pay specialconsideration against the wear, thereby realizing a clutch which islight in weight, compact in construction and long in service life. As aresult, high output can be transmitted steadily in the stepless speedchange gear of small size.

Furthermore, since each of the rollers of the rolling bearing clutch hasa circular radial section same as general roller bearings, the sameequations and factors for them can be used for calculation of theallowable surface pressure of the clutch parts.

FIG. 15 shows a mechanism of another embodiment of the stepless speedchange gear.

To the input shaft 1, a disk-like member 200 which has a center A' isfixed at an eccentric position with a distance r from the center O ofthe input shaft 1. A cam-like rotating member 400 is supported bybearings 300 rotatably at the circumferential surface of the disk-likemember 200. The other end side connecting part of the rotating member400 is rotatably connected to the other end side connecting part of aspeed change link 7 at a point B. On the other hand, one end side of anoutput connecting rod 6 is connected to a second connecting part at apoint B₁ which is in a different situation from the point B. From theabove configuration, when the input shaft 1 is rotated, the disk-likemember 200 rotates eccentrically. By this motion, the rotating member400 is moved like a link connected to a crank having a radius r(corresponds to the input connecting rod 5 in FIG. 1), swinging thespeed change link 7 around the support point Q for speed change as thecenter. In this case, since the output connecting rod 6 is connected atpoint B₁ as the second connecting part of the speed change link 7 inthis embodiment, the displacement of the output connecting rod 6 becomeslarge with the ratio QB₁ /QB, which changes the rotating speed of theoutput shaft 2 with the same ratio. Point B₁ may exist either at theinside or the outside of the point B in the line QB. The rotating speedof the output shaft 2 can be adjusted corresponding to that of the inputshaft 1 by selecting the situation of the second connecting part in theabove arrangement. Further, as the disk-like member 200 and the rotatingmember 400 are adopted in the above stepless speed change gear, thecrank and the link mechanism are composed in one unit of rotation body,and simplified. Here in FIG. 15, each notation Q, B, C, or B₁ shows theposition of the support point of the speed change lever or eachconnecting part respectively at the maximum speed change and Q', B', C'or B₁ ' shows the same position at the minimum speed change.

As described above in detail, in the first invention of the presentinvention, since the input shaft and the output shaft are connectedthrough the input shaft crank, the input connecting rod, the outputconnecting rod, the input side member, and the one way clutch in turn,and the other end side of the speed change link of which one end side isfixed at an optional position in the given moving range is connected tothe same connecting part of the input connecting rod and the outputconnecting rod, the stepless speed change gear which is securelyoperable with simple construction can be provided.

In the second invention, since the displacement of the output connectingrod differs from that of the input connecting rod by connecting theinput connecting rod and the output connecting rod at a different pointon the speed change link, the rotational speed of the output shaft canbe adjusted.

In the third invention, by adopting the disk-like member and therotating member, the crank and the link are composed in one unit as therotation body, which can simplify the mechanism.

In the fourth invention, since the other end side of the speed changelink is moved in the range from where the movement of the input sidemember becomes maximum to where it becomes minimum, the speed changeratio from maximum to minimum can be obtained effectively.

In the fifth invention, since the rolling bearing clutch is adopted asthe one-way clutch, unified load distribution can be achieved in theclutch without increasing the machining accuracy when the workingcondition changed by, for example, the change of external force appliedto the clutch or the wearing of the rollers or the rings, by thefunctions of roller bearings in the free rotation condition and theclutching function with the self alignment operation of the rollers inthe reverse rotation condition. As a result, a clutch which has largerated load, long service life and secured operation by smooth freerotation can be provided. Further, there is no need for installingadditional bearings in the shaft because the clutch itself can be usedas a bearing. Furthermore, the clutch can be operated not only underfree rotation but also under frequent repetition between the freerotation and the reverse rotation with clutching operation by providingthe annular members at both sides in the axis which stop the movement ofthe intermediate rotation bodies in the axis direction. As a result, thestepless speed change gear can be constructed in small size and lightweight and has long service life even when transmitting large power.

FIG. 16 shows a method to direct force acting on the supporting pointfor speed change Q to the input shaft 1. By using such method, the forcewhich is generated at the torque transmission and directing to thedirection of the movement of the support point becomes small. Thisarrangement facilitates the movement of the support point. For thispurpose, the relations of the positions of the center O of the inputshaft, the support point of the speed change Q, the input point B fromthe crank, the driving point B₁ to move the output connecting rod 6 andthe input point C to the one-way clutch 100 are decided to satisfy theequation:

    ∠QOB=∠B.sub.1 OB

and also the condition that the point C is situated on the extended lineof the line OQ. The support point Q is moved keeping the aboverelations. Further, the center point P of the one-way clutch 100 isdecided to realize the above relation and also to be able to input thetorque always from one direction. By such configuration, the forceapplied to the support point of speed change Q always directs to thepoint O from the balance of the vectors of the force applied to thespeed change link 7 as shown in the figure, resulting in an extremedecrease of the force which directs to the moving direction of thesupport point.

As mentioned above in detail, the present invention provides thestepless speed change gear of small size, light weight and simpleconstruction which attained stepless speed change from 0 to maximum withsmooth action, and has very high industrial applicability.

I claim:
 1. A stepless speed change gear comprising:an input shaft; aninput shaft crank fitted to said input shaft at a right angle andprovided with a connecting part; an input connecting rod connected tosaid connecting part at one end side and being provided with another endside connecting part; an output connecting rod connected to said otherend side connecting part at one end side and provided with another endside connecting part; a one-way clutch to transmit torque in onedirection only and being provided with an output shaft disposed in thesame direction to said input shaft and an input side member beingconnected to said other end side connecting part of said outputconnecting rod at one end side swingably about a center of said outputshaft; a speed change link connected to said other end side connectingpart of said input connecting rod at one end side and positioned at anoptional position in a given moving range at the other end side; fixingmeans to fix said other end side of said speed change link; said inputconnecting rod, said output connecting rod, said input side member andsaid speed change link being swingable in each plane a direction ofwhich is the same as the direction of rotation of said input shaftcrank; said other end side of said speed change link moving a givenlocus range from a position where said output connecting rod becomessubstantially orthogonal to both said speed change link and said inputside member to a position where said output connecting rod and saidspeed change link substantially line up in a straight line; said one-wayclutch being a rolling bearing clutch comprising an inner rotation body,an outer rotation body, a plurality of intermediate rotation bodies andenergizing means; said inner rotation body being provided with an innerraceway surface of a mono-hyperboloid of revolution about an axis ofsaid output shaft; said outer rotation body being provided with an outerraceway surface of a mono-hyperboloid of revolution about said axis;said inner rotation body and said outer rotation body facing each otherto form a raceway; said intermediate rotation bodies having cylindricalrolling surfaces and being disposed in the circumferential direction ofsaid raceway with their center lines slanting at a predetermined angleto a section including said axis; the surface of each intermediaterotation body contacting in line with said inner and outer racewaysurfaces; said energizing means energizing either said inner rotationbody or said outer rotation body in the direction of said axis to narrowthe spacing of said raceway; said inner and outer rotation bodies beingprovided with an annular member at an opposite side of said axis whichbrings the movement of said intermediate rotation bodies in said axialdirection to a stop; said outer rotation body being connected to saidinput side member so that both rotate in one body; said inner rotationbody being connected to said output shaft so that both rotate as onebody.
 2. A stepless speed change gear comprising:an input shaft; aninput shaft crank fitted to said input shaft at a right angle andprovided with a connecting part; an input connecting rod connected tosaid connecting part at one end side and provided with an other end sideconnecting part; an output connecting rod connected to said other endside connecting part at one end side and provided with another end sideconnecting part; a one-way clutch to transmit torque in one directiononly and provided with an output shaft disposed in the same direction assaid input shaft and an input side member connected to said other endside connecting part of said output connecting rod at one end sideswingably about a center of said output shaft; a speed change linkprovided with a second connecting part at said one end side and saidoutput connecting rod being connected to said second connecting part atsaid one end side and being positioned at an optional position in agiven moving range at the other end side; fixing means to fix said otherend side of said speed change link; said input connecting rod, saidoutput connecting rod, said input side member and said speed change linkbeing swingable in each plane a direction which is the same as thedirection of rotation of said input shaft crank; said other end side ofsaid speed change link moving a given locus range from a position wheresaid output connecting rod becomes substantially orthogonal to both saidspeed change link and said input side member to a position where saidoutput connecting rod and said speed change link substantially line upin a straight line; said one-way clutch being a rolling bearing clutchcomprising an inner rotation body, an outer rotation body, a pluralityof intermediate rotation bodies and energizing means; said innerrotation body being provided with an inner raceway surface of amono-hyperboloid of revolution about an axis of said output shaft; saidouter rotation body being provided with an outer raceway surface of amono-hyperboloid of revolution about said axis; said inner rotation bodyand said outer rotation body facing each other to form a raceway; saidintermediate rotation bodies having cylindrical rolling surfaces andbeing disposed in the circumferential direction of said raceway withtheir center lines slanting at a predetermined angle to a sectionincluding said axis; the surface of each intermediate rotation bodycontacting in line with said inner and outer raceway surfaces; saidenergizing means energizing either said inner rotation body or saidouter rotation body in the direction of said axis to narrow the spacingof said raceway; said inner and outer rotation bodies being providedwith an annular member at an opposite side of said axis which brings themovement of said intermediate rotation bodies in said axial direction toa stop; said outer rotation body being connected to said input sidemember so that both rotate in one body; said inner rotation body beingconnected to said output shaft so that both rotate in one body.
 3. Astepless speed change gear comprising:an input shaft; a disk-like memberfitted to said input shaft at an eccentric position; a rotating membersupported rotatably on a circumferential surface of said disk-likemember and provided with another end side connecting part; a speedchange link connected to said other end side connecting part of saidrotating member and positioned at an optional position in a given movingrange at the other end side; an output connecting rod connected to saidspeed change link at one end side and provided with another end sideconnecting part; a one-way clutch to transmit torque in one directiononly and being provided with an output shaft disposed in the samedirection as said input shaft and an input side member connected to saidother end side connecting part of said output connecting rod at one endside swingably about a center of said output shaft; fixing means to fixsaid other end side of said speed change link; said other end side ofsaid speed change link moving a given locus range from a position wheresaid output connecting rod becomes substantially orthogonal to both saidspeed change link and said input side member to a position where saidoutput connecting rod and said speed change link substantially line upin a straight line; said one-way clutch being a rolling bearing clutchcomprising an inner rotation body, an outer rotation body, a pluralityof intermediate rotation bodies and energizing means; said innerrotation body being provided with an inner raceway surface of amono-hyperboloid of revolution about an axis of said output shaft; saidouter rotation body being provided with an outer raceway surface of amono-hyperboloid of revolution about said axis; said inner rotation bodyand said outer rotation body facing each other to form a raceway; saidintermediate rotation bodies have cylindrical rolling surfaces and beingdisposed in the circumferential direction of said raceway with theircenter lines slanting at a predetermined angle to a section includingsaid axis; the surface of each intermediate rotation body contacting inline with said inner and outer raceway surfaces; said energizing meansenergizing either said inner rotation body or said outer rotation bodyin the direction of said axis to narrow the spacing of said raceway;said inner and outer rotation bodies being provided with an annularmember at an opposite side of said axis which brings the movement ofsaid intermediate rotation bodies in said axial direction to a stop;said outer rotation body being connected to said input side member sothat both rotate as one body; said inner rotation body being connectedto said output shaft so that both rotate in one body.